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Saturday, June 15, 2024

Electrifying the Great Western Railway

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At last, we now know that the Great Western Main Line Railway (GWML) is going to be electrified. It was way back in 1977 that the Parliamentary Select Committee on Nationalised Industries recommended considering electrification of more of Britain’s rail network. Two years later, British Rail presented a range of options that included electrifying the main line from Paddington to Swansea by the end of the century.

It was all very encouraging, but the reality today is that we only have twelve miles of electrified railway on the GWML route. It wasn’t until July last year that we really could start to believe that it was going to happen, when the government announced that work on the £5 billion investment programme would start.

It’s great news that work is underway, but what is actually happening out there? What are the detailed plans and who is going to do the work to ensure that the plans are delivered to time? To find an answer to these questions, the rail engineer recently visited Network Rail’s Lindsay Vamplew, programme director – electric trains, and Tony Walker, senior programme development manager, to find out more.

Project team in place

The project office is located in a new development sitting between Paddington Station and the canal network running alongside. The team, which includes project managers, designers, train operators and contractors, is currently about one hundred strong and growing.

Vamplew explained that the main focus is firstly to understand the shortcomings of existing electrification systems, then to design the problems out in order to emerge with a bespoke Network Rail specification. This must be compatible with the Intercity Express Programme (IEP), compliant with European standards, and world class.

Alongside this, the team needs to understand the risks and issues that will emerge when building a brand new electrification infrastructure alongside an operational railway and to validate the whole process.

The aim is to electrify the railway between London and Bristol, including Newbury and Oxford, by 2016 and extend to Cardiff by 2017. Lindsay explained that there is an aspiration to extend the work to Swansea by Easter 2018 but a decision on this has still to be made. The plan is to carry out the majority of the work during night time possessions and fortunately, unlike the WCML, they will not have to worry about re-energising the system before the next morning rush hour every day.

To ensure that the new contact system designed for Network Rail includes all the latest successful developments that have been incorporated into recent electrification projects built on the continent, the design of the power supply system is being developed by a Swiss electrification company, Furrer+Frey.

Also, to supply the power, three national grid supply points have been identified – at Didcot, Melksham and Cardiff. Tenders will be issued in early 2013 to design and build the twenty-four next-generation auto-transfer systems which will distribute power across the network.

The team is currently carrying out a comprehensive validation process of the proposed system. This work should be completed by March 2013. Lindsay was very clear that this phase of work is critical and getting it right at this stage “will ensure that the job goes well” when they start work on track.

State of the art equipment

The team is determined to use the best and most modern equipment available to get the job done. The services of the German plant suppliers Windhoff have been procured to build a suitable high-output overhead-line construction train to a specification which Network Rail has developed over the last three years. The key features of the design include the following rail-mounted plant:

• Piling machine to drive 12,000 steel tube piles of 610mm diameter;

• Concrete mixer with grab to install 2,000 bulk piles; • Steelwork erection equipment for 11,000 OLE structures;

• Equipment for installing the wires;

• Registration vehicles.

The £35 million train will complete foundations and stanchions and install the overhead line equipment as it moves. The train will be flexible and able to run to site either as one complete consist or as multiple consists. It will also be capable of installing 1.6 kilometres of electrification infrastructure per night while allowing adjacent tracks to remain open. Fabrication at the Windhoff factory is currently well advanced, and in March this year Amey was appointed to operate, maintain and deliver the OLE works using the high output overhead line construction system throughout the project.

Buried cables

Lindsay was hoping that working on Brunel’s wide gauge network would provide generous space either side of the tracks to install the additional infrastructure, but he soon found out that is not the case. There are significant lengths of well established vegetation, often valued by local communities, and there has been a policy over the years to bury signalling and power cables in the cess ways – a policy that could now cause significant difficulties.

The GWML route is rich in heritage, and includes four major tunnels (Severn, Patchway, Badminton and Box). The UNESCO World Heritage site at Bath includes an original Brunel iron bridge and there are more than 100 other listed structures including bridges, viaducts, and stations.

In addition, the underlying formation varies from London Clay to chalk and flint. This, coupled with the need to negotiate embankments, cuttings and the myriad of sensitive structures, including several Brunel-style elliptical curved arches, will not only provide an engineering challenge but will also require the team to forge good neighbourly relationships with councils, local neighbours and, of course, English Heritage.

Working relations

Tony Walker confirmed that such relationships could make or break the success of this project and they are determined to benefit from the work that they carried out on the now well-advanced Reading station project. So, to ensure that excellent public relations are maintained at all times, Tony has made presentations to many key local councils including BANES (Bath And North East Somerset) which is responsible for the World Heritage site at Bath.

A dedicated project team has been created to concentrate on the sensitive structures in Bath and along the twelve mile railway corridor to Bristol Temple Meads station, which itself is a Grade 2 listed building. The team is reviewing work carried out at York station and Durham Viaduct associated with the East Coast Main Line electrification project in the 1980s to see what lessons can be learnt and best practice adopted.

To enhance their relationship with English Heritage, Network Rail has appointed heritage specialists to give advice on sensitive design solutions for electrification. This relationship is working well and various options are currently being discussed with English Heritage, local authorities and special interest groups as the project progresses.

Tony was very pleased with the good working relationship they have with English Heritage and this positive approach has resulted in the launching of a month-long consultation on the architectural importance of a number of buildings, bridges and tunnels along the Great Western railway. This project and public consultation has ensured that, in advance of electrification, all heritage assets which deserve protection on a national scale have been identified and are being appropriately managed through the planning process.

Work on the project actually started last Christmas when a number of redundant structures were cleared and, so far, six bridges have been reconstructed. Agreements are being made with local communities to undertake local amenity improvements such as constructing paths and painting community halls in recompense for the changes and disruption that they will have to experience. The base for the project team will switch from London to Swindon as work gets underway and more train operator staff will be drafted into the team to ensure that impact of work on the day-to-day train service is minimised.

Whilst work is progressing, the signalling system will have to be immunised, signals examined and re-sited if necessary, and level crossings inspected. All this will take place alongside a significant programme of renewal including remodelling the Bristol Temple Meads and Oxford station areas, the renewal of the signalling system throughout the Great Western, Reading remodelling and, of course, let’s not forget Crossrail.

It is a challenging prospect and probably an appropriate time to remind ourselves of the potential benefits of electrification since the entire electrification project is going to cost around £5 billion.


The new Hitachi high speed electric trains now being ordered by the DfT have 20% more seats compared to diesel trains. Journey time savings can be made due to the superior braking systems, making journeys quicker, especially in urban areas where there are frequent stops.

Electric trains are cheaper to operate than diesels. They require less maintenance and have lower energy costs. They are also lighter and do less damage to the track, helping to create a more reliable railway for passengers.

Electrification should also encourage economic growth across the region by better connecting towns and cities and opening up new opportunities for businesses.

During discussions with Tony and Lindsay, it was suggested that, alongside all these benefits, there is a broader benefit which relates to the history of this world-famous route. Would not Brunel himself agree that electrification of the Great Western Main Line completes the vision of a modern railway that clearly he intended in the 1840s?

It is a perfectly reasonable assumption to make and, with the current team following a rigorous planning process, attention to detail and a determination to succeed, attributes that one would associate with Brunel, we can all look forward to travelling on a world class railway in the foreseeable future.

Hopefully, we will also be able to read some world class articles on the project along the way!


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